Coherent and Incoherent Scattering Mechanisms in Air-Filled Permeable Materials

Ultrasonic evaluation of porous materials can take advantage of some very specific acoustic phenomena that occur only in fluid-saturated consolidated solids of continuously connected pore structure. The most interesting feature of acoustic wave propagation in such media is the appearance of a second compressional wave, the so-called slow wave [1,2]. The slow compressional wave represents a relative motion between the fluid and the solid frame. This motion is very sensitive to the kinematic viscosity of the fluid and the dynamic permeability of the porous formation. Certain material properties such as tortuosity, permeability, porosity, and pore size, shape and surface quality are inherently connected to the porous nature of the material and can be evaluated best from the propagation properties of the slow compressional wave.</p

Measurement of single top-quark production in association with a W boson in the single-lepton channel at \sqrt{s} = 8\,\text {TeV} with the ATLAS detector

The production cross-section of a top quark in association with a W boson is measured using proton–proton collisions at \sqrt{s} = 8\,\text {TeV}. The dataset corresponds to an integrated luminosity of 20.2\,\text {fb}^{-1}, and was collected in 2012 by the ATLAS detector at the Large Hadron Collider at CERN. The analysis is performed in the single-lepton channel. Events are selected by requiring one isolated lepton (electron or muon) and at least three jets. A neural network is trained to separate the tW signal from the dominant t{\bar{t}} background. The cross-section is extracted from a binned profile maximum-likelihood fit to a two-dimensional discriminant built from the neural-network output and the invariant mass of the hadronically decaying W boson. The measured cross-section is \sigma _{tW} = 26 \pm 7\,\text {pb}, in good agreement with the Standard Model expectation

Search for long-lived, massive particles in events with a displaced vertex and a muon with large impact parameter in pp collisions at root s=13 TeV with the ATLAS detector

A search for long-lived particles decaying into hadrons and at least one muon is presented. The analysis selects events that pass a muon or missing-transverse-momentum trigger and contain a displaced muon track and a displaced vertex. The analyzed dataset of proton-proton collisions at √ s = 13 TeV was collected with the ATLAS detector and corresponds to 136 fb − 1. The search employs dedicated reconstruction techniques that significantly increase the sensitivity to long-lived particle decays that occur in the ATLAS inner detector. Background estimates for Standard Model processes and instrumental effects are extracted from data. The observed event yields are compatible with those expected from background processes. The results are presented as limits at 95% confidence level on model-independent cross sections for processes beyond the Standard Model, and interpreted as exclusion limits in scenarios with pair production of long-lived top squarks that decay via a small R -parity-violating coupling into a quark and a muon. Top squarks with masses up to 1.7 TeV are excluded for a lifetime of 0.1 ns, and masses below 1.3 TeV are excluded for lifetimes between 0.01 ns and 30 ns

Search for new phenomena in final states with large jet multiplicities and missing transverse momentum using s = 13 TeV proton-proton collisions recorded by ATLAS in Run 2 of the LHC

Abstract: Results of a search for new particles decaying into eight or more jets and moderate missing transverse momentum are presented. The analysis uses 139 fb−1 of proton-proton collision data at s = 13 TeV collected by the ATLAS experiment at the Large Hadron Collider between 2015 and 2018. The selection rejects events containing isolated electrons or muons, and makes requirements according to the number of b-tagged jets and the scalar sum of masses of large-radius jets. The search extends previous analyses both in using a larger dataset and by employing improved jet and missing transverse momentum reconstruction methods which more cleanly separate signal from background processes. No evidence for physics beyond the Standard Model is found. The results are interpreted in the context of supersymmetry-inspired simplified models, significantly extending the limits on the gluino mass in those models. In particular, limits on the gluino mass are set at 2 TeV when the lightest neutralino is nearly massless in a model assuming a two-step cascade decay via the lightest chargino and second-lightest neutralino

Prevalência de transtornos mentais em área urbana no norte de Minas Gerais, Brasil Prevalence of mental disorders in an urban area in Brazil

OBJETIVO: Detectar a prevalência de transtornos mentais em idosos residentes em área urbana. MÉTODOS: Uma amostra de 327 idosos (60 anos de idade ou mais) residentes na cidade de Montes Claros, no norte de Minas Gerais, foi selecionada por amostragem probabilística, em estratos múltiplos, dentro de estrato homogêneo, sendo a unidade amostral o domicílio. Os transtornos mentais foram aferidos por meio de um questionário de rastreamento psicogeriátrico (QRP). Utilizou-se análise univariada usando o qui-quadrado e análise multivariada de regressão logística. RESULTADOS: A prevalência estimada de transtornos mentais foi 29,3%, associada com sexo feminino, número de doença, capacidade funcional e local de residência (favela/não favela). CONCLUSÕES: Comparando com outros estudos comunitários, a prevalência de distúrbios mentais entre os idosos na área urbana foi alta e está associada com múltiplas doenças, incapacidade e pobreza. É uma realidade preocupante pelo de seu impacto sobre a qualidade de vida relativa à saúde da população e sobre os serviços de saúde nas próximas décadas.<br>OBJECTIVE: To detect the prevalence of mental disorders among the elderly residents of an urban area. METHODS: A sample of 327 elderly residents (60 years and older) of the city of Montes Claros, in northern Minas Gerais, was selected by means of probabilistic sampling, in multiple strata, within a homogeneous stratum. The sample unit was the home. Mental disorders were determined by means of the Short Psychiatric Evaluation Schedule (SPES). Univariate analysis was done via the chi-squared test and multivariate analysis via logistical regression. RESULTS: The estimated prevalence of mental disorders was 29.3%. Their presence was associated with female sex, number of illnesses, functional capacity and place of residence (shantytown/non-shantytown). CONCLUSIONS: Comparing the results with other community studies, the prevalence of mental disorders among the elderly in the urban area of Montes Claros was high and was associated with multiple illnesses, incapacity and poverty. This reality is a matter for concern because of its impact on quality of life relating to this population's health, and on healthcare services over the next few decades

Measurement of the jet mass in high transverse momentum Z ( → b b ‾ ) γ production at s = 13 TeV using the ATLAS detector

The integrated fiducial cross-section and unfolded differential jet mass spectrum of high transverse momentum decays are measured in Zγ events in proton–proton collisions at . The data analysed were collected between 2015 and 2016 with the ATLAS detector at the Large Hadron Collider and correspond to an integrated luminosity of . Photons are required to have a transverse momentum . The decay is reconstructed using a jet with , found with the anti- jet algorithm, and groomed to remove soft and wide-angle radiation and to mitigate contributions from the underlying event and additional proton–proton collisions. Two different but related measurements are performed using two jet grooming definitions for reconstructing the decay: trimming and soft drop. These algorithms differ in their experimental and phenomenological implications regarding jet mass reconstruction and theoretical precision. To identify Z bosons, b-tagged track-jets matched to the groomed large-R calorimeter jet are used as a proxy for the b-quarks. The signal yield is determined from fits of the data-driven background templates to the different jet mass distributions for the two grooming methods. Integrated fiducial cross-sections and unfolded jet mass spectra for each grooming method are compared with leading-order theoretical predictions. The results are found to be in good agreement with Standard Model expectations within the current statistical and systematic uncertainties

Search for nonresonant pair production of Higgs bosons in the <math display="inline"><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></math> final state in <math display="inline"><mi>p</mi><mi>p</mi></math> collisions at <math display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math> with the ATLAS detector

International audienceA search for nonresonant Higgs boson pair production in the bb¯bb¯ final state is presented. The analysis uses 126  fb-1 of pp collision data at s=13  TeV collected with the ATLAS detector at the Large Hadron Collider, and targets both the gluon-gluon fusion and vector-boson fusion production modes. No evidence of the signal is found and the observed (expected) upper limit on the cross section for nonresonant Higgs boson pair production is determined to be 5.4 (8.1) times the Standard Model predicted cross section at 95% confidence level. Constraints are placed on modifiers to the HHH and HHVV couplings. The observed (expected) 2σ constraints on the HHH coupling modifier, κλ, are determined to be [-3.5,11.3] ([-5.4,11.4]), while the corresponding constraints for the HHVV coupling modifier, κ2V, are [-0.0,2.1] ([-0.1,2.1]). In addition, constraints on relevant coefficients are derived in the context of the Standard Model effective field theory and Higgs effective field theory, and upper limits on the HH production cross section are placed in seven Higgs effective field theory benchmark scenarios

Measurements of top-quark pair differential and double-differential cross-sections in the ℓ +jets channel with pp collisions at √s=13 TeV using the ATLAS detector

Single- and double-differential cross-section measurements are presented for the production of top-quark pairs, in the lepton + jets channel at particle and parton level. Two topologies, resolved and boosted, are considered and the results are presented as a function of several kinematic variables characterising the top and t t system and jet multiplicities. The study was performed using data from pp collisions at centre-of-mass energy of 13 TeV collected in 2015 and 2016 by the ATLAS detector at the CERN Large Hadron Collider (LHC), corresponding to an integrated luminosity of 36 fb-1. Due to the large tt cross-section at the LHC, such measurements allow a detailed study of the properties of top-quark production and decay, enabling precision tests of several Monte Carlo generators and fixed-order Standard Model predictions. Overall, there is good agreement between the theoretical predictions and the data

Search for heavy diboson resonances in semileptonic final states in pp collisions at s=13 TeV with the ATLAS detector

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